I'm not so sure about this. Weidman might have the better physical assets, but a big part of St. Pierre's success is due to his gameplaning and fight IQ which I think are both still ahead of Weidman's. St. Pierre's striking is also much better than Weidman's. A weight cut usually means that a fighter may gas earlier, but Weidman's striking looked shit from the first second against Maia of all people. St. Pierre outgameplaned all of his opponents, while Weidman usually was just the physical more bad ass guy against his opponents. I'm not sure which would be more important against Silva.
Yea, I'm sure GSP has good gameplans. But better at sticking to them. But what exactly would be this special gameplan that Weidman wouldn't understand as well? The only gameplan GSP could have is get Anderson down and staying on top. Weidman has trained with GSP and has great coaching over at Serra and Renzo's camps....so I doubt game planning would be a big deal. GSP wins by being the better wrestler and having better cardio. His striking is good enough to jab the Koschecks and Shield's of the world.
I don't agree GSP has better striking. GSP is a one-dimensional striker and predictable. Anderson would easily time GSP. Weidman is also a lot more likely to end there fight, where as GSP would have no chance. Weidman has submissions and looks for them often. GSP does not. Weidman would be much stronger than GSP in a clinch vs. Anderson.
In my opinion, Weidman is the MUUUUCH tougher fight for Anderson. At 6'2, biggest frame at MW, 78inch reach, elite division 1 wrestler, with very good BJJ. Bottom line is Weidman has the wrestling and size/strength to keep Anderson down...where GSP does not. He also has more of a shot at a sub, where GSP does not. Weidman is a bigger version of GSP, with some good front headlocks.
I think most people would agree, that in a straight grappling match, Weidman houses GSP. Weidman has the size to go along with the skill.